JLPT N1Writing and careful speech

を機きにtaking … as the occasion to

A milestone arrives, and someone takes it as the moment to make a change: marriage, a move, retirement, an anniversary.

定てい年ねん退たい職しょくを機きに、私わたしは地ち域いきのボランティア活かつ動どうに参さん加かし始はじめた。

When I retired, I took the chance to start volunteering in my community.

創そう立りつ十じゅっ周しゅう年ねんを機きに、会かい社しゃは研けん修しゅう制せい度どを全ぜん面めん的てきに見み直なおした。

On its tenth anniversary, the company overhauled its training system from top to bottom.

How to form it

Noun + を機に（して）

After a verb, add の: 独どく立りつしたのを機きに. これを機きに is "taking this as my chance".

Before it: A milestone or a turning point: 結けっ婚こん, 出しゅっ産さん, 就しゅう職しょく, 引ひっ越こし, 定てい年ねん, 十じゅっ周しゅう年ねん, 法ほう改かい正せい.
After it: A fresh start or a change, usually one somebody chooses: 始はじめた, 退たい職しょくした, 見み直なおした, ことにした.
Where you'll meet it: News, company announcements, profiles, essays, and careful speech such as an interview. With friends, more often をきっかけに or just してから.

In use

姉あねは結けっ婚こんを機きに、十じゅう年ねん勤つとめた会かい社しゃを退たい職しょくした。

When she got married, my older sister left the company where she had worked for ten years.

子こどもが独どく立りつしたのを機きに、私わたしは郊こう外がいから都と心しんへ引ひっ越こすことにした。

When my child left home, I decided to move from the suburbs into the city center.

法ほう改かい正せいを機きに、業ぎょう界かい全ぜん体たいで安あん全ぜん基き準じゅんを見み直なおす動うごきが始はじまった。

The change in the law set off a move across the industry to review safety standards.

これを機きに、生せい活かつ習しゅう慣かんを見み直なおそうと思おもいます。

I'm going to take this as my chance to rethink my daily habits.

Said after a health scare, for instance.

An occasion, not a cause

The event doesn't simply make something happen: it is the moment for a new turn. A plain cause takes で.

Not said: 台たい風ふうを機きに、電でん車しゃが止とまった。

(The trains stopped because of the typhoon.)

台たい風ふうで電でん車しゃが止とまった.

Close neighbours

がきっかけで・をきっかけに・を契機にN2

きっかけ is the everyday word, and wider: whatever set something off, even a chance remark or a small thing. を契けい機きに is written, usually for a turning point in the life of a company, a town or a country.

ささいなことがきっかけで、兄あにとけんかになった。

Something trivial set off a fight with my older brother.

を境にN1

Draws a line between before and after. It doesn't say the event set the change off.

その日ひを境さかいに、彼かれは学がっ校こうに来こなくなった。

From that day on, he stopped coming to school.

に際してN2

Also "on the occasion of", but what follows is said or done for the occasion itself: thanks, a greeting, a precaution.

退たい任にんに際さいして、長なが年ねんのご支し援えんに心こころより感かん謝しゃ申もうし上あげます。

As I step down, I would like to thank you sincerely for your many years of support.

Check yourself

1Which sentence sounds natural?

Choose an answer to see why.

2Which ending fits?

定てい年ねんを機きに、（　　）。

Choose an answer to see why.

More detail

機き is the 機 of 機き会かい, opportunity, and これを機き会かいに says the same as これを機きに.

More sentences

私わたしは今こん回かいの受じゅ賞しょうを機きに、研けん究きゅう成せい果かを一いっ般ぱん向むけにも発はっ信しんしていきたい。

I'd like to take this award as my cue to start sharing my research with the general public too.

新しん社しゃ屋おくへの移い転てんを機きにして、当とう社しゃは紙かみの申しん請せい書しょを廃はい止しします。

With the move to our new headquarters, we will do away with paper application forms.

海かい外がい勤きん務むを終おえたのを機きに、彼かの女じょは働はたらき方かたを見み直なおすことにした。

On finishing her posting overseas, she decided to rethink the way she worked.

博はく物ぶつ館かんは、開かい館かん二に十じゅっ周しゅう年ねんを機きに、常じょう設せつ展てん示じを全ぜん面めん的てきに刷さっ新しんした。

For its twentieth anniversary, the museum completely renewed its permanent exhibition.